The position control for various objects has been performed using a driving element such as an actuator. For example, a tunable filter apparatus known in the art is capable of changing filter characteristics by moving a characteristic tuning member (e.g., a dielectric) closer to or away from a filter substrate. The filter characteristics of a band-pass type tunable filter apparatus, such as a center frequency of a passband, a passband width, etc., can be flexibly adjusted in accordance with a change in the condition in which the apparatus is used.
Typically, when a controlled object is moved rapidly, the position thereof overshoots a target position. Therefore, if the characteristic tuning member of the tunable filter apparatus is rapidly moved closer to the filter substrate, it may collide with the filter substrate, causing damage to the filter substrate.